Background: The PETACC-6 trial investigated the role of oxaliplatin in combination with preoperative capecitabine-based chemoradiation (CRT) and postoperative capecitabine (CT) to improve disease-free survival (DFS) in locally advanced rectal cancer. Methods: Between 11/2008 and 09/2011, 1090 patients with rectal adenocarcinoma within 12 cm from the anal verge, T3/4 and/or node-positive, with no evidence of metastatic disease and considered either resectable at the time of entry or expected to become resectable, to 5 weeks preoperative CRT with capecitabine, followed by 6 cycles of adjuvant capecitabine without (arm 1) or with oxaliplatin (arm 2) (before and after surgery). The primary analysis was intent-to-treat and adjusted for stratification factors (clinical T category, nodal status, distance from the tumor to the anal verge and method of locoregional staging) except the center. Results: An early release of DFS after a medium follow-up of 31 months per recommendation of the IDMC, did not show any difference between arms (adjusted HR = 1.04, 95% CI: 0.81 -1.33, P = 0.781) (Schmoll H et al, Proc ASCO 2014). We now report on the long-term results for DFS and OS. At median follow-up of 68 months, respectively 157 vs.156 DFS events and 97 vs. 109 deaths were observed in arm 1 and 2. In each arm, 58 patients died due to progressive disease. There is no difference in DFS between arms (adjusted HR = 1.02, 95% CI: 0.82-1.28, P = 0.835) nor in OS (adjusted HR = 1.17, 95% CI: 0.89 – 1.54, P = 0.252). 5-year DFS was 71.3% (95% CI: 67.1% - 75.0%) in arm 1, vs. 70.5% (95% CI: 66.3% - 74.3%) in arm 2. 5-year OS was 83.1 (95% CI: 79.5% - 86.1%) in arm 1, vs. 80.1% (95% CI: 76.2% - 83.4%) in arm 2. No major heterogeneity of the results for DFS according to baseline factors was identified except for the subgroup of non-german patients (N = 357) vs. german patients (N = 737) (p = 0.02 for Cochran’s Q test). Adjusted HR was 1.27 (95% CI: 0.96-1.68, p = 0.091) in disfavor of oxaliplatin in german patients while adjusted HR was 0.65 (95% CI: 0.44 – 0.97, p = 0.033) in favor of oxaliplatin in non-german patients. Conclusions: Long-term results confirm that the addition of oxaliplatin to capecitabine plus radiotherapy does not improve DFS nor OS in the ITT population. Further prognostic and predictive factors will be defined by a multivariate analysis and be presented at the meeting, in particular the discrepancy of the german and non-german patients will be clarified as well. Clinical trial information: NCT00766155